Radio receiving system



Jan. l5, 1928.

W. T. POWELL RADIO RECEIVING SYSTEM l Zlsheets-Sheet l I I Filed Sept. 22, 1922 .koLlUmz-LOU INVENTOR NNFRED T. POWE L L.

Buf1 ATroRNEY Jan. 3, 1928. 1,655,160

w. r. POWELL RADIO RECEIVING SYSTEM Filed Sept. 22, 1922 2 Sheel,s-Shee' I 2 B EATTERY INVENTOR WIHFRED 1'. POWELL BY. f

' ATTORNEY 40 herein designated A Patented vJan. l[3, 1.928.

y l 1,655,160 'PATENT OFFICE.

lvvINFRJaznT. POWELL; or noHEsTEn, NEW Yonx, AssrGNoa To THE'sTnoMBEE cAELsoN TELEPHONE MANUFACTURING COMPANY, .or ROCHESTER, NEwYoRx, A.

CORPORATION F NEW YORK.

l nai-:Io RECEIvING SYSTEM. i

Application ined september 22, 1922. serial No. 589,792.

rThis invention 'relatesfto combined automatic and radior'receiv'ing telephone systems.- It is the purposel of this invention to pro: vide a centrally located radio telephone receivin outfit which may be'remotely controlle and which will repeat signals into the transmission lines of an automatic telephone system. One of the features of the present invention is therefore the .remote control of a radio receiving outfit. 'Another feature is 'the 'arrangement'by which the radio telephone messages may be communicated to the transmission rlines of a telephone system.

Other features of this inventionlwill apf pear from the detailed description and appended claims.

Figs. 1 and 2 when taken together repreysent an automatic telephone system and a radio receiving outfit. vAt the left handside h of Fig. 1 there is represented a subscribers substation circuit, while the portion of circuits between the .dotted lines represents the ll operating circuits of a line switch,`and at the right hand side of this figure there 'appears the operating circuits of a numerical switch such as a connector switch. In Fig. 2, there is diagrammatically represented {radiotelephone receiving set of the single vacuum tube regenerative type together with the mechanism and controlling .circuits by which the various parts are remotely controlled; Fig. 3 is, a perspective view of a vario-coupler forming apart of a 'so-called A switch. Fig.

'35 4t is a perspective Y`view of a variable condenserv which is directively adjustable` by means of the mechanisms of a progressively movable switch. i

The line, switchesa's Well as he switch n and the mechanisms of the variable condenser may befof a type similar-,to that disclosed in the patent to Clement #1,107,153-Aug. 11, 1914. The A switch, however, has but a single arc Aof contacts and 4a single brush to cooperate therewith, while the brush shaft also has mounted thereon, the secondary coil 52 of a variocoupler shownin Fig. 3. I The variable con: denser operating mec anism is similar to that of the mentioned type of rotary :switches with the brushes and contacts omitted, but the brush shaft which usually carries brushes hasmounted thereon the movable plates of.

a variable condenser 56-ofzFig.' 4. The connector switch may be substantially similar to that disclosed in the patent to Keith -et al.

815,176 granted March 13, 1906.

n thlsarrangement, the subscribers who are entitled to .radio telephone service areinstructed to dial a predetermined number suchas and thereafter the radio telephone set may be remotely controlled by the calling subscriber.. In the event that other subscribers desire to listen in on the rece'iving set that has been adjusted by the first i calling subscriber the f are instructed to dial a .different predetermined number such aspl79.l

- It is believed that the invention will best be understood by-describing the method of establishing a telephone connection to the radio telephone receiving set and thereafter describing the method of variably adjusting such set. lVhen the subscriber at A removes is receiver from its switchhook, the line relay 5 is energized in a circuit extending from groundedJ battery, Winding of this re'- cut-oif` relay 6, wer the upper side of the calling line,I through Winding? of the induction coil, the microphone transmittenimpulse-springsfS, switch hook contacts 9, contacts of the key 10, lowermost armature and back contact of the cut-oit' relay 6 to'ground.

Relay 5 is energized in thiscircuit and at itsl upper armature completes an operating .circuit for the motor ma net 1,1v traceable ay upper armature and back contact of the from grounded batter winding, back contact and armature o front contact and varmature of line relay 5, inner back contact and. armature of relay 6, test brush 12 and test terminals of lbusy trunks which are characterized by the presthis magnet, upper ence of ground potential applied through' A' the lower armature and front contact of a relay similar to 13. During 'this-time a cirfcuit is closed for the out oi r'ay 6 from grounded battery, winding, back-contact and armature-of Vthe motor magnet 1 1, vwinding of out ofi' relay 6,7vlowerfront contact andarinature ofline relay`5 to ground. This circuit is ineffective at this time to o erate re# lay 6 due to the short-circuit including the `'operating circuit just described of the motor. magnet 11. A 'i When, however, the test brush 12`encounters the test terminals of an idle trunk, the

motor magnet 11 ceases its operation withy the brushes 12, 14 and 15 ot the line switch 'fin engagement with trunk leading to a connector switch. At this the terminals of an idle time the previouslydescribed circuit of cut oit relay 6is effective and it is operated to disconnect the line relay from the control of the calling line and to extend this line through line switch brush 14,and the winding of the marginal 'relay '16 to grounded battery, while the other side of the calling ground, armature and ture, frontcontact, l and winding of the cutoi' relay 6 to grounded battery, through winding of motor magnetll. This holding circuit maintains the cut 0H relay 6 operated until the time of disconnection.

' he connector'switch is now in readiness' to receive.v directive impulses from the dial sender at the calling'substation and since it has been assumed that the predetermined number for the radio telephone receiving set is 70 the calling subscriber first operates his dial sender to transmit seven impulses, in response to each of these impulses relays 16 and 17 lretract their armatures but at this time'the operation of relay 17 is of no effect. In response to'each ture of relay 16 a circuit is closed from relay, upper armature and-front contact of relay' 13, primary oli-normal springs 19,

-lay 20 and winding o 'net it advances the connector switch their primary direc-4 armatures. the connector switch receive the second serlesoflmpulses, whlch winding ot slow-releasing change-over ref t e primary motor magnet 21 to ground battery. On each completion of this circuit for the motor magbrushes 22,23 tion. transmitted by the dial sender,

and 24 one step in As` a result of the seven impulses the connector brushes are 1n operativerelation to the seventh group of circuits terminating at this switch. It' should be noted, however, that after therst'primary step of switch, the .contacts 19 are Iopened and thereafter the operating circuit of the motor magnet 21 extends from grounded battery, winding of this magnet, winding front contact and armature lof change-.over relay 20, pri

mary off-normal sprlngs 25 which are now closed, to ground. over the remalnder f the circuit which iscompleted at the armature andback contact f the relay 16.

At the -clos'e of this series of impulses, the

relay 16 maintains its armature. attracted for a relatively long time thereby interrupt ing the operated .circuit vof the change-over relay 2() and cansinor his' relay to retract its The release of relay 20, places circuits in condition to contat,

'tial so that retraction ofthe arma` back contact of this` the connector` in the case assumedis ten impulses. In response to each of these ten impulses, the relay 16 retracts its armaturev to complete a circuit from ground, its armature and back upper armature vand front contact ot' relay 13, primary oH-normal springs 25, upper armature and back contacts of relay 20, winding ot' the secondary change-over relay 26, lowermost back contact and armature ofrelay 27, conductor' 36, uppermost back .cont-act and armature of relay 28, lwinding ot secondary motor magnet 29 to groundedl battery. Under the control of this circuit, the secondary-'motor magnet advances the .brushes 22, 23 and 24 of the connector switch untilthey are opposite the tenth set of circuits in the selected group. of this series of impulses, its armature attracted for a relativel l.long interval permitting-the secondaryl c angeoverrelay 26 to deenergize. 'But, just before relay `26 deenergizes the test of the At the close relay 16 maintains called circuit is eected and since the called I circuitis idle,'its test terminal 3() is charac- `terized by the presence of Jf ull battery potenthis time'. The relays l31 and .27, however, when relay 26 deenergizes, are operated in a circuit from grounded battery, winding of relay 3l', test terminal 30, test brush 22, in'- ner left hand armature and back Contact of' relay 26, upper winding of relay 27,lower back contact and armature ofrelay-28, front contact and armature ofrelay 13 to ground. The' operation of relay'27 applies ground to the test terminal 30 to render the called circuit non-selectable, while the operation of relay 31 completes' an operating circuit for themotor magnet 32 of the A switch from grounded battery, winding, back Contact and armature of -this magnet, brush .33 in its first position, front contact and armature of relay- 31 to ground. This -circuit is eiiective to advancebrush'33 into its second position, ivh'en'a circuit-is closed ,for operating the relay 34 in series with the magnet 32. Re-A lay 34' on operationfcloses a circuit from ground through its. front contact, conductor Y 35, connector brush 23, upper winding of the trip relay 37, lowermost front Contact and armature of relay most back contact and armature of relay 28, winding OLmagnet 29 to grounded battery which operates the trip magnet to disconnect theringing current, vwhich is applied in the case of an ordinarytelephono throughsecondary oli-normalcontacts 71. As soon as relay 37 is operated itis locked and a circuit is closed from' ground, lower armature and front contact of relay' 13, lower armature and front 'contact of relay 37, lower winding of relay 28 continuity springend inner armature of re ay 37, upper armature and front contact of relay. 27, connector brush 24, back contact, continutyyspring and winding of relay 39 to the relay 28 is not operated at 27, conductor 36, upperthis circuit and locks itself operated through its continuity spring and armature to .ground at the armature and front cont-act of rela 31. The operation of relay 39 connects t e relays 40 and 41 to conductors 35 and 42 of the extended circuit. Also the o eration of relay 39 closes a circuit at its A right hand armature and front contact to advance brush 33 of the A switch into its third position. It will thus be seen thatrelays 40, 39, 41 and 43 are all operated at this time.

At the right of Fig. 2, there are shown the circuits of a vacuum tube radio receiver connected toan antenna circuit 57. This radio receiver is of a type known in the art as a regenerative receiver such as is described in y section 199, page 487 of The Principles Underlying Radio Communication prepared by the Bureau of Standards. The input circuit of this receiver including the grid and lilament of the vacuum tube 47 is variably .tuned by the variable condenser 56 4and is coupled 'to the antenna 57. The output circuit of the receiver includes the B battery 49, primary Winding of the transformer 58 and the rotor coil 52 of the vario-.coupler which is variably adjustable with respect to the coil 53, included in the input circuit of the receiver, by which the coupling between the output and input circuit is varied to control the amount of energy fed back from the output 'circuit to the input circuit. vThe output circuit ofthe radio receiver is inductively connected to the automatic telephone system through the transformer 58 and by reference to Fig. 2it will be noted that this output circuit is connected to several pairs of conductors such as 35, 42 and 59, 60, leading to connector switch termina-ls such as 61 and 62. These terminals are multiply connected through the group of connector switches which the subscribers by dialling the predetermined number may adjust to connect their several telephone lines to the radio receiver. It will be noted that the test terminals such as 63, corresponding to terminals such as 61 and 62 of the several connector switches, are not multiply connected together so that as many subscribers may establish connections to the radiolreceiver as there are connector switches in the group.

As shown in Fig. 3 the brush shaft of the rotary switch A, which carries brush 33, has.. mounted thereonmovable coil 52 of avarie-'j by a motor magnet 46, also shown in thementioned patent.

It should also be stated at this point that when relay 31 is operated the A battery' 48 is connected in a circuit to light thc lilamcnl of the vacuum tube 47, while the So-callcd B battery which is connected to the plate ol' the vacuum tube is shown at 49. The A bai'- tery 48 and the B battery 49 are distinct from the other operating battery which battery is diagrammatically represented at various positions in Figs. 1 and 2.

The calling subscriber, may now operate his dial sender springs 8 to transmit a small number of in1pu1sesand each time that these V.springs'are opened the relays 16 and 17 dcenergize. The release of relay 16 closes a circuit from ground, at its armature and back contact, back contact and armature of sensitive relay 17, secondary Of-norinal springs 50, connector brush 23, conductor 35, outer left hand armatureand front contact of relay 39, resistance 5l, left hand winding of relay 41, to grounded battery. A circuit is also closed at this time through the right hand Winding of relay 4 1 to ground through the winding ot relay 40 and to ground in multiple therewith through the lower winding of relay 28. When the mentioned circuit is closed through the left hand winding of relay 41 itincludcs the resistance 5l, which is of such value that the current through the left hand winding of relay 4l is the same as that through the right hand winding of this relay. Relay '41 is diierentially wound but as soon as the dial springs 8 are again closed relays 16 and 17v are energized to open the circuitthrough the left -hand winding of relay 41. In response to ondary winding 52 of the vario-coupler isrotated about its axis, within the primary coil 53.

In order to complete the tuning of the radio set it is only necessary for the calling party to successively operat thel push button 10.'V -This push 'button each time that 1t is operated removes a short circuit from about the resistance coil 54 which causes the marginal relay 16 to deenergize but the sensitive relay 17 remains operated. The deenergization of relay 16 opens the clrcuit of slow releasing relay 18 allowing it to release whereupon a circuit is extended from groundy at the armature and back contact of relay 16, armature and back contact of relay 18, secondary off-normal contacts 55. connector brush 24, conductor 42, frontcontact and armature of relay 39, winding of relay to ground, which short circuits and releases lrelay 40. This same ground is extended through the right hand winding of relay 41 to grounded battery, which maintains this relay energized. The release of vrelay 40 ex. tends ground from its armature and back contact through the lowermost armature and front contact of relay 43, winding of motor magnet 46 of the variable condenser to grounded battery. The motor magnet 46 thus rotates the movable plates of the variable condenser 56 shown in Fig. 4.

When the subscriber at A replaces his receiver on its-switchhook relay 16 deenerglzes and eiects the release of relay 13, which'on its deenergization eii'ects the operation of the release magnet 64 in a circuitcompleted from grounded battery, off .normal contacts 65,

back contacts and armatures of relays 13 and 16 to ground. Relay 13 on denergizationalso o ens the holding -circuit extending throng test brush 12, permitting the cut oli relay 6 to deenergize and since the line' switch is of the type that remains in the position last used the apparatus is in condition for extending anotherl calling tele hone^ line. When the connector switch is re eased from the terminals such as 30 relay 31 de energizes, which restores the. A switch to its normal position but the variable condenser however, remains in the position last used. The release ofthe connector restores relay 31 which -Aopens the circuits leading to the A battery.

What is claimed is 1. In a systemof the class described, a telephone line, a radio receiving set incl'uding a. thermionic device provided with a grid, a plate and a filament, a grid circuit including said grid and filament, a plate circuit connecting said plate and filament, said grid and plate circuits being coupled to ether, meansjincluding an automatic switchor eX- tending .said te ephone line to said radio receiving` set, and means controlled over said telephone line for `directively varying the coupling between said grid and plate circuits.

2. In a system of the class described, a telephone line, a radio set including an electron discharge device provided with a` control element, an electron emitter and an anode, an imputf circuitincluding said control element, an output circuit includin` Asaid anode and said emitter, means including an automatic switch for lextending said telephone line to said radio set, and means controlled over said telephone 'line for directively varying the coupling betweenginput and said output circuits.

3. In asyst'em of the class described, a telephone line, a radio set, a trunk and atleast one numeral switch for interconnecting said telephone line and said radio set, means including an impulse sender at said telephone line for directively operating said numerical switch to extend said last4 mentioned connection, and means includlng a differential relay directively controlled over said connection for variably operating said radio set.

4. In a system of' the class described, a telephone line, a` radio set having a plurality of adjustable tuning means, means including atleast one trunk and a numerical switch for inerconnecting said telephone line and said ra io set, means including an impulse sender at said telephone linefor directively operating said numerical switch to extend said last mentioned connection, means including a differential relay directively controlled oversaid connection by means of said impulse sender for variably operating one of said tuning means, and a manually controlled device at said telephone line for variably opermeans includlng ating another of said adjustably tuning" said last mentioned connection, means' including adiierential relay directively controlled over said connection by means of said impulse sender for variably operating one of said tuning means, and a resistance device at said telephone line for variably operating another of said adj ustab'le tuning means.

6. In a system of the class described, a final cqnnectin switch having sets of fixed contact', movab e brushes cooperating therewith, a plurality of telephonelines terminating in certain of said fixed contacts, a radio set provided with an input circuit and an output-circuit, said input' circuit having a tuning condenser', one of said circuits being electrically connected to a set of fixed contacts, a special telephone line, means for connecting said special telephone line to said automatic switch, a dial sender in said last mentioned telephone line for directively operating said automatic switch to select any of the other telephone lines and for selecting the set ofA contacts connected to said. radio set, and means controlled over said special telephoneline for progressively l telephone lines with said radio receiver, means controlled over said last signal reproducer,

means including a condenser provided with a stator unit and a rotor unit, motor mecha-J nism for progressively adjusting the setting of Said rotor, unit, means including trunks and at least one numerical switch for intern o. l n l l connecting sald telephone line and sa1d rad1o` set, means including an impulse sender of said telephone line for directively operating said numerical switch to extend said last mentioned connection, and means including said telephone line for directively operating said motor mechanism over said last mentioned connection in response to impulses.

8. In a system of the classdescribed, a lines, means including an automatic switch for interconnecting said telephone lines, a radio receiver having 'an input circuit including but a single tuning condenser, means including said automatic switchfor interconnecting one of said and mentioned telephone line for selectively adjusting the settingoi:l said tuning condenser.

9. In a s stem of the' class described, a plurality o telephone lines, means includ- 1n an automatic switch for interconnecting sald telephone lines, a radio receiver -provided with a plurality of tuning controls, means including said automatic switch for lnterconnecting one of said .telephone lines with said radio receiver, and means governed over said last mentioned telephone line for directiv'ely adjusting said tuning controls. p

10. In a system of the class described, a plurality of telephone lines, a radio receiver, mcluding a vacuum tube having a source of heat-ing current associated therewith, means includingan automatic switch for extending any of ,said telephone lines to said radio receiver, and means responsive to the connection of any of said telephone lines to said radio receiver ,for connecting the heating current to said 'vacuum tube.

11. In a system of the class described, a plurality of stations, each provided with a signal reproducer, a radio receiver, having a plurality of tuning controls, a. pair of conductors individual to each station for connecting'the signal reproducer thereof to said radio receiver, and motor devices operated over an of said pairs "of conductors for selective y actuating said tuning controls.

12. In a system of the class described, a plurality of stations, each provided with a a radio receiver includ,l

a vacuum tube and provided with a luin i raIity of tuning controls, a pair of con uc- 13. In a system of the class described, a

lplurality oftelephone lines, a radio rcceiver, including an input circuit having but a single tuning condenser for tuning said infpt circuit to various frequencies, means or connecting any of said telephone lines to said radio receiver, and means controlled over the connected telephone line for selectively adjustingthe setting of said tuning condenser.

14. In a system of the class described, a plurality of stations each provided with a signal reproducer, a lradio receiver, a pair of conductors for each station connecting the signal reproducer thereof to said radio receiver, said radio receiver having an input `circuit tuned by a condenser consisting of a stator unit and a rotor unit, and a motor device directively operated over any of said airs of conductors for rogressively adjusting the setting of saidp rotor unit.

15. In a system of the class described, a plurality of telephone lines, a radio receiver including aI vacuum tube vhaving a source of heating current associated therewith, means responsive to the connection of any of said telephone lines to saidradio receiver for connecting heating current to said vacuum tube, and means controlled over said last mentioned telephone line for selectively tuning Said radio receiver.

16, In a system of the class described, a plurality of stations, eachV station provlded with a signal receiver, a radio receiver, pairs of conductors for connecting the signal receivers of said stations to said radio receiver, said radio receiver being provided with a vacuum tube and with a plurality of tuning controls, means responsive to the connection of a pair of conductors to said radio receiver for closing a heating circuit for said vacuumv tube, and motor devices directively operated over said last mentioned pair of conductors to effect a desired setting of said tuning controls.

In witness whereof, I hereunto subscrlbe my name this 20th day of SeptemberrA. D. 1922.

WINFRED T. POWELL.

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